This application claims the benefit of Korean Patent Application No. 1999-11541 filed on Apr. 2, 1999 which is hereby incorporated by reference for all purposes as if fully set forth herein.
1. Field of the Invention
The present invention relates to a liquid crystal display device (LCD), and more particularly, to a liquid crystal display device having good aperture ratio characteristics.
2. Description of the Related Art
Regarding conventional LCDs, a plurality of gate bus lines arranged in a first direction on a first substrate and a plurality of data bus lines arranged in a second direction on the first substrate divide the first substrate into a plurality of pixel regions. A thin film transistor (TFT) applies an image signal delivered from the data bus line to a pixel electrode on a passivation layer. The TFT is formed on each pixel region and comprises a gate electrode, a gate insulator, a semiconductor layer, a source electrode, and a drain electrode.
A pixel electrode is formed on the gate insulator, thereon passivation layer is formed over the whole first substrate. A side electrode is formed surrounding the pixel electrode and a part of the pixel electrode overlaps the side electrode. Alternatively, the pixel electrode is formed on the gate insulator, and passivation layer is formed over the whole first substrate.
On the second substrate, a light shielding layer (black matrix) is formed to shield any light leakage from gate and data bus lines, and the TFT. A color filter layer is formed on the light shielding layer. An over coat layer is formed on the color filter layer. A common electrode is formed on the over coat layer. A liquid crystal layer is formed between the first and second substrates. The common electrode applies an electric field to a liquid crystal layer together with the pixel electrode.
However, the black matrix as the light shielding layer used in the LCD has some problems in aperture ratio and brightness, especially in a multi-domain liquid crystal display device which is manufactured to obtain a wide viewing angle. Multi-domain means a pixel region that is divided into at least two portions and liquid crystal molecules in the liquid crystal layer in each portion that are driven differently from each other. From the above manner, a uniform viewing angle without regard to the direction of viewing angle of the users may be obtained.
The multi-domain liquid crystal display device has a boundary region between the adjacent domains. The boundary region is an area where light leaks as well in regions such as that the gate bus line,the data bus line, the TFT.
Accordingly, the present invention is directed to an LCD that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a black matrix to shield light according to the amount of light leakage at the domain boundary regions in a multi-domain liquid crystal display device.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, a multi-domain liquid crystal display device of the present invention comprises first and second substrates facing each other, the first substrate including a thin film transistor; a plurality of gate bus lines arranged in a first direction on the first substrate and a plurality of data bus lines arranged in a second direction on the first substrate to define a plurality of pixel region, a pixel region including a plurality of domains in a shape of a stripe; a liquid crystal layer between the first and second substrates; a pair of electrodes driving the liquid crystal layer; and a plurality of black matrix the region of the plurality of gate and data bus lines, the thin film transistor and at the boundaries of adjacent domains in the pixel region, the plurality of black matrix having different widths.
The pixel region may be divided into two or four domains in the shape of a stripe and the width of the black matrix at a middle boundary and an end part of domains is wider than the width of the black matrix in the other region.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.